A5101000821- Glass properties and applications
- Physics of Superconductivity and Magnetism
- Nonlinear Optical Materials Research
- Luminescence and Fluorescent Materials
- Photorefractive and Nonlinear Optics
- Photoreceptor and optogenetics research
- Synthesis and characterization of novel inorganic/organometallic compounds
- Phase-change materials and chalcogenides
- Silicon Nanostructures and Photoluminescence
- Magnetic properties of thin films
- Imbalanced Data Classification Techniques
- Advanced Chemical Physics Studies
- Organic and Molecular Conductors Research
- Superconducting and THz Device Technology
- Organometallic Compounds Synthesis and Characterization
- Anomaly Detection Techniques and Applications
- Thin-Film Transistor Technologies
- Advanced Optical Sensing Technologies
- Optical Systems and Laser Technology
- Adaptive optics and wavefront sensing
- Superconductivity in MgB2 and Alloys
- Conducting polymers and applications
- Molecular Junctions and Nanostructures
- Solid-state spectroscopy and crystallography
- Advanced Condensed Matter Physics
University of Utah
1990-1992
Femtosecond dynamics of photogenerated quasiparticles in ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\delta}}}$ superconducting thin films shows, at T\ensuremath{\le}${\mathit{T}}_{\mathit{c}}$, two main electronic processes: (i) quasiparticle avalanche production during hot-carrier thermalization, which takes about 300 fsec; (ii) recombination to form Cooper pairs, is completed within 5 psec. In contrastr, nonsuperconducting epitaxial...
We have measured the femtosecond dynamics of nonlinear optical response χ(3) in polydiethynylsilane (C4H2SiBu2)x, a novel class π-conjugated polymers incorporating Si, using degenerate four-wave mixing and photoinduced absorption techniques. In resonance conditions at 620 nm we found χ(3)=3×10−9 esu, which decays record time 135 fs, followed by slower decay component 750 without long tail even high laser intensities. This material is an excellent candidate for devices sub-THz frequency range.
Degenerate four-wave mixing with femtosecond time resolution is used to measure the magnitude and transient response of third-order nonlinear optical susceptibility χ(3) (ω;ω,−ω,ω) at 620 nm in nonoriented conducting polymers including polydiacetylene, <m1;38p>polyacetylene, polyaniline, polydiethynylsilane, polythiophene, polythiophene derivatives. <m1;40p>Resonant nonresonant excitations influence χ(3). <m1;39p>The electronic instantaneous for...
A Comment on the Letter by G. L. Eesley et al. Phys. Rev. Lett. 65, 3445 (1990).Received 7 March 1991DOI:https://doi.org/10.1103/PhysRevLett.67.1053©1991 American Physical Society
The transient electronic response of epitaxially grown YBa/sub 2/Cu/sub 3/O/sub 7- delta / superconductor thin films in the femtosecond time domain was investigated using photoinduced reflectivity ( Delta R) with 60-fs resolution. For temperatures T>T/sub c/, only a bolometric signal observed R>0. T<T/sub R<0 temperature-dependent rise on order 300 fs observed, followed by relaxation (on 3 ps) into state results for c/ are explained terms quasi-particle (QP) giving R<0. Thus, is interpreted...
LTAO (Laser Tomography Adaptive Optics), there are errors occur from adaptive optics and those due to laser tomography. This paper focuses on the analysis of under various operational conditions in
The ultrafast photocarrier dynamics in polysilane alloys, amorphous (SiH2)n, has been studied using the picosecond photoinduced absorption (PA) technique. For excitation below optical gap, PA response decays exponentially and is faster at low temperatures. This interpreted terms of e-h geminate recombination small clusters (∼10 Å) a-Si:H embedded matrix. with above-gap similar to that conventional a-Si:H; it much slower form a power law t −β (β&lt;1), independent spectral range between...